Summary

Recommendation ITU-T H.450.3 describes the procedures and the signalling protocol for the call diversion supplementary service (SS-DIV) in ITU-T H.323 (packet-based multimedia communications systems) networks. This Recommendation comprises the services call forwarding unconditional (SS-CFU), call forwarding busy (SS-CFB), call forwarding no reply (SS-CFNR) and call deflection (SS‑CD).

SS-CFU, SS-CFB, SS-CFNR and SS-CD are supplementary services which apply during call establishment providing a diversion of an incoming call to another destination endpoint.

This Recommendation makes use of the "generic functional protocol for the support of supplementary services in ITU-T H.323 systems" as defined in Recommendation ITU-T H.450.1.

The procedures and the signalling protocol of this Recommendation are derived from the call diversion supplementary service specified in ISO/IEC 13872 and ISO/IEC 13873.

The revision approved in May 2011 corrects errors discovered in the initial publication.